Exhaust line for automobile

ABSTRACT

An exhaust line connected to the engine of an automobile, includes:
         a manifold ( 5 ) including at least one exhaust gas circulation channel ( 16 ) having an exhaust gas outlet ( 19 ), the manifold ( 5 ) including an outlet flange ( 13 ) through which the exhaust gas outlet ( 19 ) extends;   a downstream apparatus ( 7 ) having an exhaust gas inlet ( 27 ) connected to the exhaust gas outlet ( 19 ) of the manifold ( 5 ), the downstream apparatus ( 7 ) being rigidly connected to the outlet flange ( 13 ) of the manifold ( 5 ). The engine ( 3 ) includes an engine block and a cylinder head ( 15 ), and the exhaust line ( 1 ) includes attachment elements ( 33 ) for attaching the outlet flange ( 13 ) of the manifold ( 5 ) directly to the engine block or the cylinder head ( 15 ).

The present invention generally concerns exhaust lines for automobiles.

More precisely, the invention concerns an exhaust line provided to be connected to the engine of an automobile, the exhaust line being of the type comprising:

-   -   a manifold inwardly including at least one exhaust gas         circulation channel having an exhaust gas outlet, the manifold         comprising an outlet flange through which the exhaust gas outlet         extends;     -   a downstream apparatus having an exhaust gas inlet connected to         the exhaust gas outlet of the manifold, the downstream apparatus         being rigidly connected to the outlet flange of the manifold.

The downstream apparatus is typically a turbocompressor, which itself is connected to a catalytic purification member. These two apparatuses have a significant mass.

In FR 2 856 735, a support structure is provided to fasten the catalytic purification member and the turbocompressor on the engine block. This support structure picks up part of the weight of the catalytic purification member and the turbocompressor and transmits it to the engine block. The other part of the weight is picked up by the outlet flange of the manifold. This manifold is connected by an inlet flange on the cylinder head of the engine. The outlet flange, which picks up part of the weight of the turbocompressor and the catalytic purification member, has a fairly significant overhang in relation to the inlet flange. Because of this, it is necessary to dimension the enclosure of the manifold and the upstream and downstream flanges accordingly. Moreover, the support attached to the engine block is complex and costly.

In this context, the invention aims to propose an exhaust line that is less complex and less costly, while also ensuring effective maintenance of the apparatus(es) located downstream of the manifold.

To that end, the invention concerns an exhaust line of the aforementioned type, characterized in that the engine comprises an engine block and a cylinder head, the exhaust line comprising means for attaching the outlet flange of the manifold directly to the engine block or cylinder head.

The exhaust line can also have one or several of the features below, considered individually or according to all technically possible combinations:

-   -   the attaching means comprises at least one elongated attaching         member, having a first end portion connected to the outlet         flange and a second end portion connected to the engine block or         the cylinder head;     -   the attaching means comprises at least one spacer inserted along         the or each attaching member between the outlet flange and the         engine block or cylinder head, with or without the insertion of         an inlet flange of the manifold;     -   the attaching member is of the type chosen from the group         comprising a screw, a threaded rod, a stud or a tierod;     -   the circulation channel of the exhaust gases has at least one         exhaust gas inlet capable of being connected to an outlet of the         combustion chamber of the engine, the manifold including at         least one inlet flange passed through by the exhaust gas inlet,         the attaching member passing through the inlet flange;     -   the outlet flange is substantially parallel to the or each inlet         flange;     -   the outlet flange is inclined in relation to the or each inlet         flange;     -   the manifold comprises an enclosure inwardly defining the         exhaust gas circulation channel, the outlet flange being welded         to the enclosure;     -   the downstream apparatus has a companion flange passed through         by the exhaust gas inlet of the downstream apparatus, the         companion flange being rigidly attached to the outlet flange of         the manifold;     -   the companion flange is attached to the outlet flange of the         manifold using the means for attaching the outlet flange to the         engine block or the cylinder head;     -   the downstream apparatus has an inlet duct defining the exhaust         gas inlet, the inlet duct being welded on the outlet flange of         the manifold; and

the manifold includes an enclosure inwardly defining the exhaust gas circulation channel and an intermediate flange welded to the enclosure, the outlet flange being rigidly attached to the intermediate flange of the manifold.

Other features and advantages of the invention will emerge from the detailed description thereof provided below, for information and non-limitingly, in reference to the appended figures, among which:

FIG. 1 is a top view of a first embodiment of the invention;

FIG. 2 is a view similar to that of FIG. 1, for a second embodiment of the invention;

FIG. 3 is a view similar to FIG. 1, for a third embodiment of the invention;

FIG. 4 is a view similar to FIG. 1, for a fourth embodiment of the invention;

FIG. 5 is a side view of an alternative embodiment of the invention wherein the outlet flange is perpendicular to the inlet flange;

FIG. 6 is a perspective view of the upstream and downstream flanges of FIG. 5;

FIG. 7 is a front view of the upstream and downstream flanges of FIG. 6.

The exhaust line 1 illustrated in FIG. 1 is provided to be connected to the engine 3 of an automobile.

The exhaust line includes, from upstream to downstream in the direction of circulation of the exhaust gases, a manifold 5 provided to capture the exhaust gas coming out of the combustion chambers of the engine, a turbocompressor 7, a catalytic purification member (not shown), and other equipment not shown, such as a muffler. At its downstream end, the exhaust line includes a cannula (not shown) making it possible to release the purified exhaust gas into the atmosphere.

The manifold 5 includes an inlet flange 9 for attaching to the engine, an enclosure 11 and an outlet flange 13 for attaching to the turbocompressor 7.

The inlet flange 9 is rigidly attached on the cylinder head 15 of the engine.

The enclosure 11 inwardly defines an exhaust gas circulation channel 16 having four inlets 17 and one outlet 19. Each inlet 17 is provided to be placed to coincide with the exhaust gas outlet of one of the combustion chambers of the engine. Thus, each inlet 17 is connected to the outlet of one of the combustion chambers of the engine and is capable of capturing the exhaust gases coming out of the corresponding combustion chamber.

The inner channel 16 includes four inlet sections 21 each defining an inlet 17. The inlet sections 21 emerge in an outlet section 23 defining the outlet 19.

The inlets 17 pass through the inlet flange 9. The outlet 19 passes through the outlet flange 13.

The turbocompressor 7 includes an inlet duct 25 inwardly defining an exhaust gas inlet 27. The inlet 27 is placed to coincide with and is sealably attached to the exhaust gas outlet 19 of the manifold.

In the embodiment of FIG. 1, the turbocompressor 7 includes a companion flange 29 rigidly attached to the outlet flange 13. The flange 13 and the companion flange 29 are typically attached to each other by bolts 31. The inlet duct 25 is for example welded on the companion flange 29. The exhaust gas inlet 27 passes through the companion flange 29. The flange 13 and the companion flange 29 are pushed against each other and are parallel to each other.

To ensure that the stresses applied to the outlet flange 13 are directly picked up by the engine, the exhaust line includes means 33 for attaching the outlet flange 13 of the manifold directly to the cylinder head 15.

The means 33 comprises at least one elongated attaching member 35, and preferably comprises several elongated attaching members 35. It for example comprises three or four attaching members 35, each ensuring attaching of the outlet flange 13 directly to the cylinder head 15.

Each attaching member is connected to the outlet flange 13 by a first end 37 and is connected to the cylinder head 15 by a second end 39.

The attaching member 35 is for example a screw or a threaded rod or a bolt or a lug stud, or a tierod.

In one embodiment, each attaching member 35 passes through the inlet flange 9 by a hole 41 provided to that end. In this case, the attaching means 33 includes spacers 43 inserted along each attaching member 35 between the inlet flange 9 and the outlet flange 13. The spacer 43 is for example a rigid metal cylinder in which the member 35 is engaged. The member 35 passes through the spacer 43 over the entire length thereof. The spacer 43 bears by one end on the inlet flange 9 and by its opposite end on the outlet flange 13.

Each attaching member 35 passes through the outlet flange 13 by orifices 45 provided to that end. In the case where the attaching member is a screw, the end 37 is the head of the screw, and the end 39 corresponds to a threaded portion of the screw. The head 37 bears on a face 47 of the outlet flange turned opposite the cylinder head 15. The threaded end 39 is screwed into a corresponding tapped housing 49 of the cylinder head 15.

The holes 41 and 45, formed in the upstream and downstream flanges to allow the screw 35 to pass, are not tapped. Thus the screw is free in relation to the inlet flange.

In the embodiment of FIG. 1, the screw 35 is screwed by its end 39 into the tapped housing 49. Due to the tractive force exerted by the head of the screw 37 towards the cylinder head 15, the spacer 35 is squeezed between the flanges 9 and 13.

The inlet flange 9 is typically attached to the cylinder head 15 by screws, engaged in holes 52 provided to that end, and illustrated in FIG. 6.

The attaching members 35 can be not screws, but rather bolts. In this case, the member 35 includes a screw and a nut. The head of the screw is mounted as in FIG. 1. However, the threaded end of the screw passes all the way through an orifice formed in the web of the cylinder head, a nut being screwed on the threaded end of the screw so as to press the web of the cylinder head and the inlet flange 9 against each other. In the case where the attaching head 35 is a rod whereof both ends are threaded, one of the threaded ends is mounted so as to pass all the way through one of the orifices 45 of the outlet flange 13, a nut being screwed on the threaded end of the rod. The opposite end of the threaded rod can be screwed into a tapped housing as shown in FIG. 1. Said end can also pass through a non-tapped orifice of a web of the cylinder head, and receive a nut.

Alternatively, the end 37 of the attaching member could be threaded, and the orifice 45 tapped, the end 37 thus being screwed into the orifice 45.

Preferably, the orifices 45 are distributed around the orifice of the corresponding flange 13 at the outlet 19. For example, the attaching means 33 can include four attaching members 35, engaged in four orifices 45 occupying the apices of a square, the outlet 19 occupying the center of said square.

Likewise, there can for example be four bolts 31 for attaching the companion flange 29 to the outlet flange 13 and said bolts can be arranged at the apex of a square whereof the outlet 19 constitutes the center. The bolts 31 are closer to the outlet 19 than the attaching members 35.

A second embodiment of the invention is shown in FIG. 2. Only the points by which the second embodiment differs from the first will be described below. Elements that are identical or ensure the same function in both embodiments will be designated by the same references.

In the first embodiment, the companion flange 29 is smaller than the outlet flange 13. In the second embodiment, the companion flange 29 is substantially the same size as the outlet flange 13. Moreover, the exhaust line does not include specific means for ensuring the attaching of the outlet flange 13 to the companion flange. Indeed, the outlet flange 13 is attached to the companion flange 29 via attaching members 35.

To that end, the companion flange 29 includes holes 51 arranged to coincide with the orifices 45 of the outlet flange 13. The attaching members 35 pass through both the holes 51 and the orifices 45.

When for example the attaching members are screws, the head 37 of the screw bears on a face 53 of the companion flange turned opposite the cylinder head 15.

Thus, the flange and the companion flange are squeezed between the head 47 of the screw on one hand, and the spacer 43 on the other.

Alternatively, the hole 51 could be tapped, and the fastening member 35 could include an end portion 37 to be threaded screwed into the tapped hole 51.

A third embodiment of the invention is illustrated in FIG. 3. Only the points by which the third embodiment differs from the first will be described here. Elements that are identical or ensure the same function in both embodiments will be designated by the same references.

In the embodiment of FIG. 3, the turbocompressor does not include a companion flange 29. The duct 25 is directly welded on the outlet flange 13.

However, the manifold includes an intermediate flange 55 welded to the enclosure 11. The outlet 19 passes through both the intermediate flange 55 and the outlet flange 13.

The outlet flange 13 is pushed against a face of the intermediate flange 55 turned opposite the cylinder head 15. The outlet flange and the flange 55 are rigidly attached to each other by bolts 57. The intermediate flange 55 is smaller than the outlet flange 13. The bolts 57 are arranged closer to the outlet 19 than the attaching members 35. They are for example arranged like the bolts 31 of the first embodiment.

A fourth embodiment of the invention is illustrated in FIG. 4. Only the points by which this fourth embodiment differs from the first will be described here. Elements that are identical or ensure the same function in both embodiments will be designated by the same references.

In the fourth embodiment, the turbocompressor does not include a companion flange 29, and the manifold does not include an intermediate flange 55. The enclosure 11 of the manifold is welded directly on a face 59 of the outlet flange 13 turned towards the cylinder head. The duct 25 of the turbocompressor is rigidly attached, for example by a seam weld, on a face 61 of the outlet flange 13 situated opposite the cylinder head 15.

In the embodiments of FIGS. 1 to 4, the outlet flange 13 is planar, as is the inlet flange 9. The upstream and downstream flanges are substantially parallel to each other.

On the contrary, in the embodiment of FIGS. 5 to 7, the outlet flange 13 extends substantially perpendicular to the inlet flange 9. For example, the inlet flange 9 extends in a substantially vertical and transverse plane, the outlet flange 13 being in a substantially horizontal and transverse plane. In this case, the inlets 17 of the exhaust gas circulation channel through the manifold are oriented substantially longitudinally. The outlet flange 13 is placed above the enclosure 11, the outlet 19 being oriented vertically upward. The inlet duct 25 of the turbo manifold is situated above the outlet flange 13.

Thus, the outlet flange 13 has large opposite faces 63 and 65. The flange 13 is also laterally defined by a face 67 turned towards the cylinder head 15. The face 67 extends parallel to and opposite the flange 9. In the embodiment of FIGS. 5 to 7, the spacers 43 are inserted between the face 67 and the flange 9.

Moreover, in the embodiments of FIGS. 1 to 4, the attaching members 35 were substantially perpendicular to the flanges 9 and 13. In the embodiment of FIGS. 5 to 7, the attaching members 35 are substantially parallel to the outlet flange 13, i.e. parallel to the large faces 63 and 65. The attaching members 35 remain perpendicular to the inlet flange 9.

The outlet flange 13 includes two orifices 69 for receiving attaching members 35. These orifices 69 pass completely through the outlet flange from a face 71 opposite the cylinder head 15 to the face 67. In the case where the attaching members are screws, the heads 37 of the screws bear on the face 71.

The exhaust line described above has multiple advantages.

Because the exhaust line comprises attaching means for attaching the outlet flange of the manifold directly to the engine block or the cylinder head, the stresses applied to the outlet flange are picked up by the cylinder head or the engine block through the attaching means. These stresses do not pass through the enclosure or the upstream flange.

This makes it possible to reduce, if necessary, the thickness of the inlet flange and possibly the thickness of the manifold enclosure. This also makes it possible to dimension the means for attaching the inlet flange on the cylinder head or the engine block.

This is even more important given that the outlet flange is generally staggered in relation to the upstream flange, with a significant overhang. Thus, the stresses applied to the outlet flange create a significant torsion torque at the attaching points of the inlet flange to the engine.

Using elongated attaching members, for example screws, lug studs or any other similar attaching member, makes it possible to perform the attachment particularly simply. The attaching means does not include complicated support pieces. The attaching means does not significantly increase the weight of the exhaust line.

Preferably, securing studs that are already provided on the engine are used to attach the upstream flange. In this case, the means for attaching the outlet flange to the engine practically does not increase the weight of the exhaust line at all.

The outlet flange can have any sort of orientation of the upstream flange. It is not necessarily parallel to the upstream flange.

Moreover, there are multiple possibilities for making the connection between the outlet flange and the enclosure of the manifold, and the connection between the outlet flange and the apparatus downstream therefrom, for example the turbocompressor.

Thus, the invention makes it possible to obtain a connection between the outlet flange and the cylinder head or engine block particularly simply and economically.

The exhaust line described above can have multiple alternatives.

The outlet flange can be attached either to the engine block or the cylinder head of the engine.

The number of attaching members varies. The means for attaching the outlet flange can comprise a single attaching member or two, three or even four or more attaching members.

The attaching members can be arranged in variable positions in relation to the outlet flange. Thus, two attaching members can be arranged above the exhaust gas outlet. According to another alternative, two attaching members can be placed below the exhaust gas outlet. Two attaching members can also be provided on one of the sides of the exhaust gas outlet, or three attaching members arranged in a triangle, etc. The number of attaching members and their arrangement are determined by the stresses to be picked up by the outlet flange and transmitted to the cylinder head or engine block. It should be noted that attaching means for attaching the outlet flange of the manifold directly to the engine block or to the cylinder head refers to means capable of transmitting the majority of the stresses undergone by the outlet flange to the cylinder head or to the engine block, without passing through other elements of the manifold like the enclosure or the upstream flange.

The members for attaching the outlet flange to the engine block or to the cylinder block can, depending on the case, pass through or not pass through the upstream flange. Indeed, on many engines, lug studs are provided to attach the upstream flange. The inlet flange therefore includes orifices in positions connected with the studs provided on the engines. Preferably, lug studs are used as members for attaching the outlet flange. Holes are thus provided in the outlet flange opposite holes in the inlet flange and connected with the lug studs of the engine. In this case, the traction exerted towards the engine by the end of the fastening member on the outlet flange is transmitted to the spacer, then to the upstream flange. The latter part is thus pushed against the cylinder head or the engine block.

Moreover, other lug studs can be used exclusively to attach the inlet flange on the engine block or the cylinder head.

To attach the outlet flange, it is possible to have both attaching members that pass through the inlet flange and others that do not pass through the upstream flange. It is also possible to have only attaching members that pass through the inlet flange or only attaching members that do not pass through the upstream flange.

The downstream apparatus rigidly attached to the outlet flange of the manifold is not necessarily a turbocompressor. This apparatus can also be a catalytic purification device or any other element of the exhaust line.

The manifold cannot have a single inlet flange, but include several separate flanges, one per exhaust gas inlet in the manifold.

The manifold can include four, five, or more than five inlets, or fewer than four inlets.

The spacer 43 can have any sort of section. It can have a round, square, rectangular, etc. section. The section can be open or closed.

In the case where the attaching member passes through the upstream flange, the spacer bears on one hand on the inlet flange and on the other hand on the outlet flange.

In the case where the attaching member does not pass through the upstream flange, the spacer can bear on one hand on the cylinder head or the engine block and on the other hand on the outlet flange.

The spacer can be rigidly attached on the outlet flange and/or on the upstream flange, by any suitable means, for example by a seam weld.

Moreover, the manifold can include contacts making the downstream manifold integral with the upstream manifold. Each contact thus has a first end rigidly attached, for example by welding, on the downstream manifold, and a second end attached to the upstream manifold, for example by welding. These contacts make it possible to transmit the stresses undergone by the outlet flange directly to the upstream flange.

Depending on manufacturing constraints, the spacers are either attached to, or integral with the flange. 

1. An exhaust line provided to be connected to the engine of an automobile, the exhaust line (1) comprising: a manifold (5) inwardly including at least one exhaust gas circulation channel (16) having an exhaust gas outlet (19), the manifold (5) comprising an outlet flange (13) through which the exhaust gas outlet (19) extends; a downstream apparatus (7) having an exhaust gas inlet (27) connected to the exhaust gas outlet (19) of the manifold (5), the downstream apparatus (7) being rigidly connected to the outlet flange (13) of the manifold (5), characterized in that the engine (3) comprises an engine block and a cylinder head (15), the exhaust line (1) comprising attaching means (33) for attaching the outlet flange (13) of the manifold (5) directly to the engine block or the cylinder head (15).
 2. The exhaust line according to claim 1, characterized in that the attaching means (33) comprises at least one elongated attaching member (35), having a first end portion (37) connected to the outlet flange (13) and a second end portion (39) connected to the engine block or the cylinder head (15).
 3. The exhaust line according to claim 2, characterized in that the attaching means (33) comprises at least one spacer (43) inserted along the or each attaching member (35) between the outlet flange (13) and the engine block or cylinder head (15), with or without the insertion of an inlet flange (9) of the manifold (5).
 4. The exhaust line according to claim 2, characterized in that the elongated attaching member (35) is of the type chosen from the group comprising a screw, a threaded rod, a lug stud, or a tierod.
 5. The exhaust line according to claim 2, characterized in that the circulation channel (16) of the exhaust gases has at least one exhaust gas inlet (17) capable of being connected to an outlet of the combustion chamber of the engine, the manifold (5) including at least one inlet flange (9) passed through by the exhaust gas inlet (17), the attaching member (35) passing through the inlet flange (9).
 6. The exhaust line according to claim 5, characterized in that the outlet flange (13) is substantially parallel to the or each inlet flange (9).
 7. The exhaust line according to claim 5, characterized in that the outlet flange (13) is inclined in relation to the or each inlet flange (9).
 8. The exhaust line according to claim 1, characterized in that the manifold (5) includes an enclosure (11) inwardly defining the exhaust gas circulation channel (16), the outlet flange (13) being welded to the enclosure (11).
 9. The exhaust line according to claim 8, characterized in that the downstream apparatus (7) has a companion flange (29) passed through by the exhaust gas inlet (27) of the downstream apparatus (7), the companion flange (28) being rigidly attached to the outlet flange (13) of the manifold.
 10. The exhaust line according to claim 9, characterized in that the companion flange (29) is attached to the outlet flange (18) of the manifold (5) using the means (33) for attaching the outlet flange (13) to the engine block or the cylinder head (15).
 11. The exhaust line according to claim 8, characterized in that the downstream apparatus (7) has an inlet duct (25) defining the exhaust gas inlet (27), the inlet duct (27) being welded on the outlet flange (13) of the manifold (5).
 12. The exhaust line according to claim 1, characterized in that the manifold (5) includes an enclosure (11) inwardly defining the exhaust gas circulation channel (16) and an intermediate flange (55) welded to the enclosure (11), the outlet flange (13) being rigidly attached to the intermediate flange (55) of the manifold (5).
 13. The exhaust line according to claim 3, characterized in that the elongated attaching member (35) is of the type chosen from the group comprising a screw, a threaded rod, a lug stud, or a tierod.
 14. The exhaust line according to claim 3, characterized in that the circulation channel (16) of the exhaust gases has at least one exhaust gas inlet (17) capable of being connected to an outlet of the combustion chamber of the engine, the manifold (5) including at least one inlet flange (9) passed through by the exhaust gas inlet (17), the attaching member (35) passing through the inlet flange (9).
 15. The exhaust line according to claim 4, characterized in that the circulation channel (16) of the exhaust gases has at least one exhaust gas inlet (17) capable of being connected to an outlet of the combustion chamber of the engine, the manifold (5) including at least one inlet flange (9) passed through by the exhaust gas inlet (17), the attaching member (35) passing through the inlet flange (9). 